<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> 平级选择器。平级 </title>
    <style>
        .item {
            color: blue;
        }

        .item:hover {
            font-size: 60px;
            color: green;
        }

        .item+li {
            color: red;
        }

        .item~li {
            font-size: 80px;
        }
    </style>
</head>

<body>
    <ul>
        <li>元素1</li>
        <li>元素2</li>
        <li class="item">元素3</li>
        <li>元素4</li>
        <li>元素5</li>
    </ul>
</body>

</html>